Egypt's opposition Islamists increased their seats in parliament nearly six-fold after an election marred by violence, but President Hosni Mubarak's party retained a big majority, official results showed on Thursday. A rights group said at least eight people were killed on Wednesday in clashes with security forces who cordoned off polling stations in areas with strong Muslim Brotherhood support. The Brotherhood says it won 11 seats, bolstering its parliamentary bloc in the month-long elections to 87 -- its strongest showing ever. The results were nearly six times its strength in the outgoing chamber and more than double its wins in its previous strongest showing in 1987. "There are results which were rigged," deputy Brotherhood leader Mohamed Habib told Reuters. But "it is an achievement despite these dramatic conditions," he told Reuters.